Evaluating and Enhancing Information Dissemination in Urban Areas of Interest using Opportunistic Networks

(c) 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works[EN] Opportunistic networks can provide an alternative way to support the diffusion of information in special locations within a city, particularly in crowded spaces, where current wireless technologies can exhibit congestion issues. The efficiency of this diffusion relies mainly on user mobility. In fact, mobility creates the opportunities for contacts and, therefore, for data forwarding. This paper is, therefore, mainly focused on evaluating the dissemination of information in urban scenarios with different crowd densities and renewal rates. Through observation, we obtained real data from a local subway station and a plaza. These data were used, in combination with a pedestrian mobility simulator, to generate people mobility traces. We evaluated the diffusion of messages in these scenarios using the direct and the epidemic protocols. Experimental results show that content diffusion is mainly affected by two factors: degree of mobility and message size. Although it is well known that increasing the node density increases the diffusion rate, we show that, when keeping node density fixed, higher renewal rates cause the delivery ratio to drop. Moreover, we found that the relation between message size and contact duration is also a key factor, demonstrating that large messages can lead to a very low overall performance. Finally, with the aim of increasing the diffusion effectiveness of large messages, we propose an improvement over the Epidemic protocol, named EpidemicX2, based on the fragmentation of the data to be sent. The results show that the delivery ratio is increased, and the average delivery time is reduced, with no substantial increase in terms of overhead.This work was supported by the Ministerio de Economia y Competitividad, Spain, under Grant TEC2014-52690-R, and in part by the Secretaria Nacional de Educacion Superior, Ciencia, Tecnologia e Innovacion del Ecuador, Ecuador.Chancay-Garcia, LJ.; Hernández-Orallo, E.; Manzoni, P.; Tavares De Araujo Cesariny Calafate, CM.; Cano, J. (2018). Evaluating and Enhancing Information Dissemination in Urban Areas of Interest using Opportunistic Networks. IEEE Access. 6:32515-32531. https://doi.org/10.1109/ACCESS.2018.2846201S3251532531

An Analytical Model Based on Population Processes to Characterize Data Dissemination in 5G Opportunistic Networks

(c) 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.[EN] The scarcity of bandwidth due to the explosive growth of mobile devices in 5G makes the offloading messaging workload to Wi-Fi devices that use opportunistic connections, a very promising solution. Communications in mobile opportunistic networks take place upon the establishment of ephemeral contacts among mobile nodes using direct communication. In this paper, we propose an analytical model based on population processes to evaluate data dissemination considering several parameters, such as user density, contact rate, and the number of fixed nodes. From this model, we obtain closed-form expressions for determining the diffusion time, the network coverage, and the waiting time. Newer 5G wireless technologies, such as WiGig, can offer multi-gigabit speeds, low latency, and security-protected connectivity between nearby devices. We therefore focus our work on the impact of high-speed and short-range wireless communications technologies for data dissemination in mobile opportunistic networks. Moreover, we test whether the coexistence with a fixed infrastructure can improve content dissemination, and thus justify its additional cost. Our results show that, when user density is high, the diffusion is mainly performed through the opportunistic contacts between mobile nodes, and that the diffusion coverage is close to 100%. Moreover, the diffusion is fast enough to dynamically update the information among all the participating members, so users do not need to get closer to fixed spots for receiving updated information.This work was supported in part by the Ministerio de Economa y Competitividad, Spain, under Grant TEC2014-52690-R, Grant MTM 2016-75963-P, and Grant SEV-2013-0323, in part by Generalitat Valenciana, Spain, under Grant AICO/2015/108 and Grant ACOMP/2015/005.Hernández-Orallo, E.; Murillo Arcila, M.; Cano, J.; Tavares De Araujo Cesariny Calafate, CM.; Conejero, JA.; Manzoni, P. (2018). An Analytical Model Based on Population Processes to Characterize Data Dissemination in 5G Opportunistic Networks. IEEE Access. 6:1603-1615. https://doi.org/10.1109/ACCESS.2017.2779748S16031615

How Human Mobility Models Can Help to Deal with COVID-19

[EN] One of the key factors for the spreading of human infections, such as the COVID-19, is human mobility. There is a huge background of human mobility models developed with the aim of evaluating the performance of mobile computer networks, such as cellular networks, opportunistic networks, etc. In this paper, we propose the use of these models for evaluating the temporal and spatial risk of transmission of the COVID-19 disease. First, we study both pure synthetic model and simulated models based on pedestrian simulators, generated for real urban scenarios such as a square and a subway station. In order to evaluate the risk, two different risks of exposure are defined. The results show that we can obtain not only the temporal risk but also a heat map with the exposure risk in the evaluated scenario. This is particularly interesting for public spaces, where health authorities could make effective risk management plans to reduce the risk of transmission.Hernández-Orallo, E.; Armero-Martínez, A. (2021). How Human Mobility Models Can Help to Deal with COVID-19. Electronics. 10(1):1-24. https://doi.org/10.3390/electronics1001003312410

Analytical evaluation of the performance of contact-based messaging applications

Communications in mobile opportunistic networks, instead of using the Internet infrastructure, take place upon the establishment of ephemeral contacts among mobile nodes using direct communication. In this paper, we analytically model the performance of mobile opportunistic networks for contact-based messaging applications in city squares or gathering points, a key challenging topic that is required for the effective design of novel services. We take into account several social aspects such as: the density of people, the dynamic of people arriving and leaving a place, the size of the messages and the duration of the contacts. We base our models on Population Processes, an approach commonly used to represent the dynamics of biological populations. We study their stable equilibrium points and obtain analytical expressions for their resolution. The evaluations performed show that these models can reproduce the dynamics of message diffusion applications. We demonstrate that when the density of people increases, the effectiveness of the diffusion is improved. Regarding the arrival and departure of people, their impact is more relevant when the density of people is low. Finally, we prove that for large message sizes the effectiveness of the epidemic diffusion is reduced, and novel diffusion protocols should be considered. © 2016 Elsevier B.V. All rights reserved.This work was partially supported by Ministerio de Economia y Competitividad, Spain (Grants TEC2014-52690-R & MTM2013-47093-P & SEV-2013-0323), Generalitat Valenciana, Spain (Grants AICO/2015/108 & ACOMP/2015/005) and by the Basque Government through the BERC 2014-2017 program.Hernández Orallo, E.; Murillo Arcila, M.; Tavares De Araujo Cesariny Calafate, CM.; Cano Escribá, JC.; Conejero Casares, JA.; Manzoni, P. (2016). Analytical evaluation of the performance of contact-based messaging applications. Computer Networks. 111:45-54. https://doi.org/10.1016/j.comnet.2016.07.006S455411

The fans united will always be connected: building a practical DTN in a football stadium

Football stadia present a difficult environment for the deployment of digital services, due to their architectural design and the capacity problems from the numbers of fans. We present preliminary results from deploying an Android app building an ad hoc network amongst the attendees at matches at Brighton and Hove Albion's AMEX stadium, so as to share the available capacity and supply digital services to season ticket holders. We describe the protocol, how we engaged our users in service design so that the app was attractive to use and the problems we encountered in using Android

Automation and Control of Vehicle Flow using Raspberry Pi

The number of vehicles in the world's cities increases exponentially, this is the case of Latin American cities, and particularly in the city of Portoviejo, province of Manabí in Ecuador, has been growing considerably in recent years, the city has been expanding towards its surroundings. Due to this big number of vehicles, which also adds little planning to improve the use of public transport, little planning to improve urban vehicular flow, the centralization of administrative area and main shops in the city, are the main reasons why in certain times of the day the traffic can become a little slow. Universidad Técnica de Manabí, has the objective of modernizing the improvement of vehicular flow in its surroundings and in addition to automating the vehicular entrance to its facilities through the automation of the respective permit for visiting drivers and staff. In this paper we show the methodology and tools necessary to create a system to control vehicles entry and exit using a Raspberry Pi, an analysis of the different technologies that can be used to improve vehicular flow is also included, approaching the Internet of Things

Intercontact times in opportunistic networks and their impact on forwarding convergence

The increasing popularity of some new mobile technologies (smartphones for example) has opened new interesting scenarios in communications because of the possibility of a device to communicate with another one without using the wireless (or wired) network interfaces but taking advantages of the mobility of all the devices. In this direction, one of the most important evolution of Mobile ad hoc networks are opportunistic networks, that are self-organizing networks where there are not any guarantee of two devices to be linked with complete multi-hop path in any time. What a node has to do to deliver a certain message, is to nd a space-time multi-hop path, that is portions of path that can carry on the message during the time until it reaches the destination. We can see an example in Figure 1: the source S has to deliver a message to the destination D; the message can arrive at D at time t3, even if in [t1,t3] S and D are not directly linked. As nodes do not have any knowledges of the network topology, but only of the destination the massage have to arrive to, this way of delivering needs at any time to make some decisions, that are to whom has to be sent message and how many copies has to be sent

Intelligent spectrum management techniques for wireless cognitive radio networks

PhD ThesisThis thesis addresses many of the unique spectrum management chal- lenges in CR networks for the rst time. These challenges have a vital e ect on the network performance and are particularly di cult to solve due to the unique characteristics of CR networks. Speci cally, this thesis proposes and investigates three intelligent spectrum management tech- niques for CR networks. The issues investigated in this thesis have a fundamental impact on the establishment, functionality and security of CR networks. First, an intelligent primary receiver-aware message exchange protocol for CR ad hoc networks is proposed. It considers the problem of alleviat- ing the interference collision risk to primary user communication, explic- itly to protect primary receivers that are not detected during spectrum sensing. The proposed protocol achieves a higher measure of safeguard- ing. A practical scenario is considered where no global network topology is known and no common control channel is assumed to exist. Second, a novel CR broadcast protocol (CRBP) to reliably disseminate the broadcast messages to all or most of the possible CR nodes in the network is proposed. The CRBP formulates the broadcast problem as a bipartite-graph problem. Thus, CRBP achieves a signi cant successful delivery ratio by connecting di erent local topologies, which is a unique feature in CR ad hoc networks. Finally, a new defence strategy to defend against spectrum sensing data falsi cation attacks in CR networks is proposed. In order to identify malicious users, the proposed scheme performs multiple veri cations of sensory data with the assistance of trusted nodes.Higher Committee For Education Devel- opment in Iraq (HCED-Iraq

THE KNOWLEDGE MANAGEMENT – NECESSITY FOR THE MODERNIZATION OF THE ORGANIZATIONS

If individuals and technologies can harmonize their intelligence under various forms, only the intelligent organizations will have the capacity to transform and coordinate these abilities for their own advantage by using informational technologies, by combining the most advanced software technologies with the newest management instruments in order to produce extremely efficient organizations. The information excess is a chronic phenomenon for the modern organization, so that the lack of the capacity to filter and use relevant information is a consequence of the inefficiency to manage the knowledge fund, of the lack of a clear strategy with a common purpose for personnel and team. Today, almost the intelligent organizations must manage and apply the entire knowledge fund, they must use instruments and technologies in order to build an informational architecture, having as a purpose the competitiveness in a turbulent and changing environment. The apportion of the information and knowledge of the organization, the exchange of information between employees, departments and even other companies are facilitated by the information and communication technology. Not all information are valuable, but in order to establish what information respond to the questions What? Where? How? When? and Why? instruments of knowledge management are needed in order to determine what knowledge is qualified to be intellectually active.knowledge, knowledge management, intelligent organization, informational technologies, knowledge exchange, collaborative networks, apportion intelligent instruments